Bonanza is an American western television series that ran on NBC from September 12, 1959, to January 16, 1973. Lasting 14 seasons and 431 episodes, Bonanza is NBC’s longest-running western, and ranks overall as the second-longest-running western series on U.S. network television (behind CBS’s Gunsmoke), and within the top 10 longest-running, live-action American series. The show continues to air in syndication. The show is set in the 1860s and it centers on the wealthy Cartwright family who live in the vicinity of Virginia City, Nevada, bordering Lake Tahoe. The series initially starred Lorne Greene, Pernell Roberts, Dan Blocker and Michael Landon and later featured (at various times) Guy Williams, David Canary, Mitch Vogel and Tim Matheson. The show is known for presenting pressing moral dilemmas.

The title “Bonanza” is a term used by miners in regard to a large vein or deposit of silver ore, from Spanish bonanza (prosperity) and commonly refers to the 1859 revelation of the Comstock Lode of rich silver ore mines under the town of Virginia City, not far from the fictional Ponderosa Ranch that the Cartwright family operated. The show’s theme song, also titled “Bonanza”, became a hit song. Only instrumental renditions, absent Ray Evans’ lyrics, were used during the series’s long run.